Estudo da aderência entre barras de aço e concreto de alto desempenho reforçado com fibras metálicas.

Abstract

Concrete consists of one of the materials most used in construction. Several advances have been made in order to obtain a concrete with better characteristics and one of them consists of high performance concrete (CAD). From additives and additions, this type of concrete achieves excellent properties, where one of the ways of obtaining these results is the incorporation of steel fibers into the cementitious matrix. However, there are several gaps to be filled in regard to their properties, such as bond, which is one of the key factors for a smooth operation of the concrete and should be carefully considered. Considering the context, this work consists in proposing an analysis of the influence of the addition of steel fibers in the steel­concrete bond through the push­out test. For this analysis prismatic test pieces with a 20 cm edge and 2.5Ø anchorage length were made using steel bars in the diameters of 10, 12.5 and 16 mm and concrete compressive strength of 60 MPa. In addition to the effect of the fibers, the correlation between the diameter of the bar and the maximum bond strength was evaluated. Through the results obtained, it was possible to verify that the addition of steel fibers improves the bond strength as well as the compressive strength of the concrete, where the diameter that presented the best results was 16 mm. In addition, it was possible to conclude that the theoretical results, provided by the ABNT NBR 6118/2014 expression were inferior to those obtained experimentally.